Real-time data from the voyage confirms that this dual propulsion approach is not only technically feasible, but also impactful: The vessel’s GHG emissions on the current voyage meet the 2050 Fuel EU Maritime GHG intensity targets and IMO’s GFI Direct Compliance targets at least until 2044.

Suction sails surpass energy-harvesting expectations

The power of wind-assisted propulsion has been tested through Bow Olympus’ two first cross-Atlantic voyages. The four 22-meter suction sails have been operational under varying weather conditions, with the performance closely monitored by Odfjell’s crew and technology team on board and onshore.

“The results have surpassed our expectations,” confirms VP Technology Erik Hjortland. “Even in good, but not perfect, wind conditions, we observed a 15-20% energy-saving effect. That translates to five tons of fuel saved per day, equivalent to a reduction of 15 tons of CO₂ emissions per day. On certain parts of the current voyage, we have seen up to 40% fuel consumption reductions. These are very promising figures. We are thrilled to note that our initial calculations are confirmed and even exceeded.”

Using a new type of AI-based weather routing system allowed the five-year-old 49k dwt vessel to take full advantage of the prevailing wind conditions.

Dual propulsion solution moves the needle towards net zero

In addition to the sails, Odfjell decided to double the exploration and added another element to Bow Olympus’ current Atlantic crossing: 100% sustainable biofuel. The goal was to explore a pathway towards near-net-zero operations for a deep-sea vessel. The bunkered biofuel was sourced from certified sustainable waste materials. The certification body is accredited by both IMO and EU.

As Bow Olympus reaches European shores this weekend, she has demonstrated that the dual propulsion solution is a realistic pathway to carbon neutrality for deep-sea shipping, 25 years ahead of time: The voyage shows a full 85% reduction in GHG intensity compared to conventional fuels, without technical investments or upgrades required to consume the fuel. In addition, the energy efficiency is improved by 15-20% by the use of sails.

Passing the Fred Hartman Bridge in Houston. Video by Robert Land Productions and Mihovil Photography

Testing novel innovations while remaining fuel flexible

Over the past decade, Odfjell has installed more than 140 energy-saving devices on its vessels, improving carbon intensity by more than 53% compared to the 2008 IMO baseline. Having exhausted most conventional upgrades, Odfjell is now focused on next-generation solutions—such as wind propulsion—to meet its 2030 goal of 57% carbon intensity reduction.

To move the needle beyond 57%, a fuel switch is required. Odfjell has chosen to remain flexible, keeping all doors open at a time when the fuel of the future for shipping remains undecided. The choice of biofuel for this proof-of-concept voyage was done to demonstrate one of the pathways.

“We will now drill into the data, assess the lessons learned, and use the experience as a foundation to decide our next steps. There are unknown variables yet to be clarified, such as the impact of varying weather conditions, trade lanes, vessel configurations, etc. Still, I am positive that we have begun charting a credible course toward carbon neutrality,” Hjortland concludes.